Rotary drive connection for casing drilling string

ABSTRACT

A drive connection for connecting a rotary power source to a string of well casing employed as a rotary drilling string. The drive connection is designed to be insertible in the upper end of the casing and is provided with a mandrel carrying slips and a slip expander for gripping the interior of the casing and pipegripping shoes operable in response to angular movement of the mandrel to apply torsional force to the casing.

United States Patent 1191 Brown July 24, 1973 [54] ROTARY DRIVECONNECTION FOR 3,075,584 1/1963 Brown 166/210 X NG RI STRING 3,096,8247/1963 Brown.... 166/138 X 1,813,459 7/1931 Miller 294/8625 X [7Inventor: Cicero Brown, 5429 Sturbndge 2,771,957 11/1956 Weber 279/2Dr., Houston, Tex. 77027 2,719,051 9/1955 Hankins, Jr... 294/8625 Filed;J y 1970 2,914,330 11/1959 Wheeler 279/2 21 'A l. No.: 52,517 PrimaryExaminer-Andrew R. Juhasz Assistant Examiner-Z. R. Bilinsky Related US.Application Data Attorney R werlin [63] Continuation-impart of Ser. No.778,509, Nov. 25,

a 3 552 507 57 ABSTRACT [52] US. Cl 166/237, 166/78, 294/8625 A driveconnection for connecting a rotary power [51] Int. Cl E21b 23/00 urce toa string of well casing employed as a rotary [58] Field of Search 279/2;294/8621, ril ing string. The drive connection is designed to be294/8624, 86.25, 86,29, 93, 94, 95; 166/138, insertible in the upper endof the casing and is provided 200, 98, 78, 216, 119, 237 with a mandrelcarrying slips and a slip expander for gripping the interior of thecasing and pipe-gripping [56] References Cited shoes operable inresponse to angular movement of the UNITED STATES PATENTS mandrel toapply torsional force to the casing.

1,650,102 11/1927 Tschappat. 166/78 x 2 Claims, 5 Drawing FiguresPATENTED M24973 SHEET 1 BF 2 .4 T OEIVE) ROTARY DRIVE CONNECTION FORCASING DRILLING STRING RELATED APPLICATION This application is acontinuation-in-part of my cpending U. S. Pat. application Ser. No.778,509, filed Nov. 25, 1968, now U.S. Pat. No. 3,552,507.

BACKGROUND OF THE INVENTION SUMMARY OF THE INVENTION The presentinvention is directed to the novel rotary drive connection itself. Thelatter, in accordance with an illustrative embodiment, comprises atubular mandrel'connectible to the drive swivel of the power source andinsertible into the bore of the casing. The mandrel carries a set ofwedge-shaped pipe gripping slips mounted for radial movementinto and outof gripping engagement with the casing and an expander'threadedlymounted on the mandrel for longitudinal movement into and out of wedgingengagement with the slips in response to relative rotation of themandrel. Also carried by the mandrel below the slipsis a set of rockablymounted pipe-gripping shoes, operable in response to angular movement ofthe mandrel to apply torsional force to the casing in response torotation of the mandrel so as to rotationally drive the casing.

This drive connection provides a very simple and effe ctive means forreleasably connecting the power source to the casing drill string, aswhen adding to or removing sections therefrom, or when inserting orreceiving the bit assembly.

Other and more specific objects and advantages of this invention willbecome more readily apparent from the following detailed descriptionwhen read in conjunction with the accompanying drawing which illustratesa useful embodiment in accordance with this invention.

In the drawing:

FIG. I is a longitudinal, partly sectional view of the drive connectionshown inserted in the upper end of a casing drilling string andconnected to a rotary power unit; 1

FIG. 2 is a longitudinal, partly sectional view of the drive connectionshowing the parts in their retracted non-driving relation to the casing;similar to F IG. 2 showing the parts FIG. 3 is aview in the casing driverelation; m 4 FIG. 4 is a cross-sectional view taken on line 4-4 of FIG.2 showing the parts of the torsional drive elements in their non-drivingposition, and

FIG. 5 is a view similar to FIG. 4 showing the torsional drive elementsin their drive position.

Referring to the drawing, FIG. 1 shows the drive connection assembly,designated generally by the numeral 10, inserted into the upper end of astring of casing C which is to function as the rotary drill string andextends into the upper end of well W lined with a conductor pipe Ksurmounted by a wellhead fitting F which includes a conventional slipbowl H adapted to receive hanger slips G (shown in broken lines) forsupporting the casing string at appropriate stages of operation.

Drive connector assembly 10 includes a tubular mandrel or support member11 having an axial bore 12 and provided with a threaded box 13 at itsupper end for connection to a power source. A tubular bushing 14 isrotatably mounted about the upper portion of the mandrel onanti-friction bearings 15 and has a radially extending flange 16dimensioned to rest on the upper end of the uppermost section of easingC which will normally project upwardly above the upper end of the wellbore. Flange 16 forms stop means engageable with the upper end of thecasing section to limit inward movement of the connection assembly intothe bore of the casing. The inner end of bushing 14 carries an inwardlyturned lip 17 on which a plurality of pipe-gripping wedges or slips 18are hingedly supported by means of outwardly projecting hanger lips 19formed on the upper ends of the slips. An upwardly and inwardly taperingconical expander 20 is disposed about mandrel 11 between the latter andslips 18 and is provided internally with a section of relatively coarseright-hand threads 21 engageable by a complementary section of threads22 formed on mandrel 11 intermediate the ends thereof. With thisright-hand threaded connection between the expander and the mandrel itwill be seen that right-hand rotation of the mandrel will cause expander20 to move upwardly relative to slips 18, the complementary taperedsurfaces thereof cooperating to move the slips outwardly into grippingengagement with the wall of easing C. Reverse rotation of the mandrelwill move the expander downwardly to release the slips from grippingengagement with the casing.

The lower portion of expander 20 is provided with an annular outwardlyopening recess 23 defined by a cylindrical bottom wall24 and at itsouter end by oppositely extending annular lips 25-25.

Pipe-engaging elements, designated generally by the numeral 26, aremounted in recess 23 and are operable in response to angular movement ofthe mandrel to apply torsional force to the casing. This form of thegripping elements 26 is described in detail in my U. S. Pat. No.3,322,006, issued May 30, 1967, and constitute casing-gripping meanswhich are non-threadedly engageable with the casing for transmittingrotational torque thereto. While the specific details of thesecasing-gripping elements do not form a part of the present invention inview of the earlier patent thereon, a brief description will be helpfulin connection with the present disclosure.

Mounted within recess 23 concentrically with bottom wall 24 is a pair ofgenerally semi-circular pipe-gripping shoes 27 which are normallyurgedapart radially by means of relatively light coil springs 28 seatedin suitable sockets 29 in the opposed ends of the shoes, as best seen inFIGS. 4 and 5, thespacing between the inner ends of the shoes permittinga limited amount of independent movement of the shoes. The upper andlower end edges of the shoes are provided with oppositely extendingupper and lower flanges 3030 which are adapted to engage lips 25-25,whereby the latter willprevent the shoes from being radially expelledfrom recess 23. Each of the shoes is provided centrally on its externalsurface with a longitudinally extending convex, generally smooth arcuatesurface portion 31, which has a circular radius adapted to providesmooth or non-gripping engagement with the inner wall of a surroundingpipe, such as well casing C. Surface portion 31 extends for a relativelyshort angular distance about the outer periphery of the shoes. On eachside of surface portion 31 the exterior of the shoes is off-set slightlyradially inwardly at 32 and these radially off-set portions are providedwith a few parallel, longitudinally extending, radially projecting teeth33, which are normally out of contact with casing C when portion 31 isengaged with the casing wall. The teeth 33 are adapted, upon relativerotation or oscillation between the shoes and casing C, to engage thecasing and prevent further relative rotation between the shoes and thecasing, and to then apply a strong torsional force to the casing inresponse to rotational force transmitted from the expander body to theshoes. By reason of the longitudinally extending form of the teeth, somelongitudinal slippage between the teeth and the casing can occur, eventhough the torsional force will prevent relative rotation between theteeth and the casing, as will appear subsequently. To effect relativerotation or rocking movement of the shoes, bottom wall 24 is machined toprovide oppositely radially extending lugs 34, the lugs on oppositesides of recess 23 having openings 35 through whicha cylindrical shaft36 extends. A series of rollers 37 are mounted on each shaft 36 onopposite sides of the lugs 34 and constitute cam followers, the sets ofthe cam followers thus being mounted on diametrically opposite sides ofrecess 23. The inner periphery of shoes 27 on each side of the centralportion thereof is provided with non-circular cam surfaces 38 which areengageable by cam followers 37 in response to relative angular movementbetween expander and the shoes. As best seen in FIG. 5, cam surfaces 38are shown engaged with cooperating cams 37 to rock shoes 27 angularlyrelative to casing C, so as to project teeth 33 into torsional grippingengagement with the wall of casing C.

The lower end portion of expander 20 is provided about the exteriorthereof below recess 23 with an annular seal element 39 arranged forslidable sealing engagement with casing C and an internal annular sealelement 40 arranged for slidable sealing engagement with the exterior ofmandrel 11. Upper and lower stop collars 41 and 42, respectively, aremounted about mandrel 11 above and below the ends of the connectorassembly to limit the extent of relative longitudinal movement betweenthe mandrel and the other parts of the assembly.

Mandrel 11 is adapted to be connected by means of box 13 through a drivenipple 43 to the tubular drive spindle 44 ofa rotary power unit 45 ofany well known construction. The latter may be electrically operated ormay be fluid pressure-operated such as described in my U. 8; Pat. No.3,467,202, issued Sept. 16, 1969. Power unit 45 is carried on a swivel46 suspended in a well derrick (not shown) on elevators 47 connected tothe conventional drawworks (not shown) of a drilling rig, by means ofwhich the power unit and the elements connected thereto may be raisedand lowered relative to the well as required in the course ofoperations. Swivel 46 is provided with a goose neck 48 through whichdrillingfluid may be circulated through passages communicating with thebores of spindle 44, nipple 43 and bore 12 of mandrel ll whence thefluid will be directed through casing C to the bit assembly (not shown)to the various discharge passages normally provided therein.

OPERATION Connector assembly 10 suspended from power unit 45 will belowered into the upper end of casing C until flange 15 rests on theupper end of the casing (FIG. 2). Right-hand rotational movement willnow be imparted by the power unit to mandrel 11 causing expander 20 tomove upwardly relative to the mandrel and thereby setting slips 18 intothe wall of easing C (FIGS. 1 and 3). Because of the longitudinalarrangement of teeth 33 on shoes 27, pipe-gripping units 26 will slideupwardly on the casing wall for the distance required to accommodate theslip-setting movement of the expander. As slips 18 are tightly set,however, further rotational force applied to mandrel 11 will produce therelative angular movement operative to rock shoes 27 to positions atwhich such rotational force will be transmitted through teeth 33 asdriving torque to the casing. As soon as slips 18 are set, hanger slipsG may be removed freeing the casing string for rotation transmitted frompower unit 45 to connector assembly 10.

To remove the connector assembly, as whennecessary to add anothersection to the casing string, the string may again be suspended andanchored in hanger slips G, whereupon, reverse or left-hand rotation ofspindle 44 by the power unit for only a few turns will be sufficient toback expander 20 away from slips 18, releasing the latter from theirgripping engagement with the casing. The connector assembly can now bepulled out of the top of the casing. A new section of easing may now beattached to the upper end of the casing string hanging in the wellheadfitting, and connector assembly 10 inserted in the upper end of theadded casing section, and re-actuated by right-hand rotation of themandrel. Hanger slips G may now be removed and drilling continued.

It will be understood that various alterations and modifications may bemade in the details of the illustrative embodiment within the scope ofthe appended claims but without departing from the spirit of thisinvention.

What I claim and desire to secure by Letters Patent 1s:

1. A rotary drive connection for well casing, comprismg:

a. a connector assemblage bodily insertible into the upper end of thebore of a well casing, said assemblage including:

i. a tubular mandrel adapted to be connected to a rotary drive powersource;

ii. pipe-gripping slips mounted about the mandrel for radial movementinto and out of gripping engagement with the casing;

iii. expander means mounted on the mandrel for axial movement into andout of wedging engagement with said slips in response to rotation ofsaid mandrel; and

iv. pipe-engaging shoes rotatably mounted about said expander means forangular movement thereby into non-threaded, torque-transmittingengagement with the casing so that upon rotation of said mandrel saidexpander actuates said pipegripping slips into engagement with saidcasing and upon further rotation said mandrel actuates saidpipe-engaging shoes into engagement with said casing. 2. A rotary driveconnection according to claim 1 including stop means on the mandreladapted to engage the upper end of the casing to limit inward movementof said assemblage.

4' i l ll

1. A rotary drive connection for well casing, comprising: a. a connectorassemblage bodily insertible into the upper end of the bore of a wellcasing, said assemblage including: i. a tubular mandrel adapted to beconnected to a rotary drive power source; ii. pipe-gripping slipsmounted about the mandrel for radial movement into and out of grippingengagement with the casing; iii. expander means mounted on the mandrelfor axial movement into and out of wedging engagement with said slips inresponse to rotation of said mandrel; and iv. pipe-engaging shoesrotatably mounted about said expander means for angular movement therebyinto non-threaded, torquetransmitting engagement with the casing so thatupon rotation of said mandrel said expander actuates said pipe-grippingslips into engagement with said casing and upon further rotation saidmandrel actuates said pipe-engaging shoes into engagement with saidcasing.
 2. A rotary drive connection according to claim 1 including stopmeans on the mandrel adapted to engage the upper end of the casing tolimit inward movement of said assemblage.